﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Input;
using System.Diagnostics;

namespace CKSE.ViewModels
{
    public class RelayCommand : ICommand
    {
        #region Events
        public event EventHandler CanExecuteChanged
        {
            add
            {
                CommandManager.RequerySuggested += value;
            }
            remove
            {
                CommandManager.RequerySuggested -= value;
            }
        }
        #endregion

        #region Fields
        private readonly Action<object> _execute;
        private readonly Predicate<object> _canExecute;
        #endregion
        
        #region Life Cycle
        public RelayCommand(Action<object> execute)
            : this(execute, null)
        {

        }

        public RelayCommand(Action<object> execute, Predicate<object> canExecute)
        {
            if (execute == null)
            {
                throw new ArgumentNullException("execute");
            }
            _execute = execute;

            _canExecute = canExecute;
        }
        #endregion

        #region Methods
        [DebuggerStepThrough]
        public bool CanExecute(object parameter)
        {
            return _canExecute == null ? false : _canExecute(parameter);
        }       

        public void Execute(object parameter)
        {
            _execute(parameter);
        }
        #endregion
    }
}
